Kernel Bug Tracker – Bug 44221
Acer Aspire AO531h (among other netbooks) requires reboot=b,f
Last modified: 2015-02-19 16:39:03 UTC
Created attachment 74721 [details]
My Acer Aspire AO531h can start up and shut down just fine, but reboot locks up the machine with the bottom left lights and the HD light all lit like the fourth of July.
This has been happening in Ubuntu 11.10 and 12.04.
Older versions of Ubuntu, as well as the newest crunchbang, all work just fine.
I have started a bug over at Launchpad, and here is the url:
uname -r reports it is using 3.5.0-030500rc5-generic.
I have attached:
lspci -vvnn output.
I followed the step by step instructions on how to do this here:
I hope this helps, I seriously do not have a clue where this bug report belongs.
Created attachment 74731 [details]
Created attachment 74741 [details]
Created attachment 74751 [details]
Created attachment 74761 [details]
Where can be hard to guess.
If you do the following what occurs
boot with the kernel option init=/bin/sh
at the shell prompt
Also if you go to a text mode console and do a reboot -f does that hang in the same way ?
(problem is it could be hanging for various reasons including driver shutdown, BIOS funnies so it's sometimes fun trying to figure out the culprit)
I tried both reboot -f and init=/bin/sh, both do nothing to solve this.
Thanks for the suggestions though.
another thing to check is that if you boot the machine and at the grub menu fro which kernel hit ctrl-alt-del does the box then hang rather than reboot ?
If that does work then it means the bios is probably ok, if that fails then you've got a BIOS problem.
If it succeeds then try the boot options for how to reboot
are the two most likely ones
how do you use the reboot=bios or reboot=kbd options?
If I could add to this, same problem with an Acer Aspire D257-N57 netbook, shutdown works fine, 12.04 precise fresh install.
Ctrl-alt-del works from the grub menu. However, I have done a sudo reboot from the shell to see what it would hang on and all it did was logout from my current user and produce a root shell, although I'm not entirely sure if this is a related issue.
edit: details on a root shell being produced are not related, separate issue.
I have the same machine, and had the same reboot problem on Ubuntu 12.04 LTS.
After countless combinations of suggestions made on the Web, I concluded solving mine with these, in terminal:
1. gksudo gedit /etc/default/grub
2. I found the line: GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
3. Changed it to: GRUB_CMDLINE_LINUX_DEFAULT="quiet splash reboot=b,f"
4. Saved and closed the file
5. sudo update-grub
Then, I shut it down, opened again, tried to reboot, and worked fine!
Thanks - thats really useful to confirm.
(In reply to comment #13)
> Thanks - thats really useful to confirm.
I was so enthusiastic to post my first contribution to the solution of a bug, that I didn't check which one of the two parameters b (for bios) or f (for force) is used by the kernel. After the heat's gone, I can confirm that "reboot=b" works for me, and "reboot=f" not.
So, Alan, yes, you were right to advise experimenting with the reboot parameters.
I should lastly say that if after my step 5. I try reboot directly, as some people advise, it will hang again. It must be shut down first.
Created attachment 104671 [details]
Patch to force reboot type to bios for Acer Aspire AO531h
Dennis, Danis, please confirm whether this bug is still present in the latest kernel (3.10-rc5)
If the bug is still present, please revert any boot line quirks and try the attached patch. Please let me know if it's successful so we can get this bug closed.
Anon, please post your dmidecode output and I'll modify the patch to target your model of laptop too :)
Sorry I can't confirm, I no longer own that machine. I traded it for a Compaq CQ57.
Before testing my proposed patch, Danis tested the latest kernel after revoking kernel boot parameter 'reboot' in grub. He confirms that this bug is no longer present in the latest kernel.